1. Field of the Invention
The present invention relates to a flexible magnetic disc having an improved dimensional shrinkage factor.
2. Description of the Related Art
A conventional flexible magnetic disc is produced by blanking a disc from a polyethylene terephthalate film of about 75 .mu.m in thickness both surfaces of which are coated with magnetic layers of 0.5 to 3.0 .mu.m in thickness. Since the polyethylene terephthalate film used as a substrate is hot stretched during the film production and further it is under tension during the production from the magnetic film, the film suffers from heat shrinkage when heated. Accordingly, when signals are recorded on the magnetic disc at the lower temperature, the magnetic disc is stored at a higher temperature and then the recorded signals are reproduced at a lower temperature, the degree of off-track of a magnetic head becomes large during reproduction because of heat shrinkage of the magnetic disc. Particularly, in the case of the flexible magnetic disc having a large tracking density, off-track causes errors.